Hunted down original source, but can't read it because am neither a subscriber to 'Science' nor a member of the AAAS, & don't want to pay. You may want to try it.Estimating the Size of the World's Threatened Flora Nigel C. A. Pitman and Peter M. Jørgensen Science 2002 November 1; 298: 989 (in Brevia) http://www.sciencemag.org/cgi/content/full/298/5595/989/DC1This is not related to www.angryflower.com